1. Field of the Invention
This invention relates to a process cartridge using an electrophotographic method or an electrostatic recording method and an image forming apparatus using the process cartridge.
2. Description of Related Art
To form images, image forming apparatuses using an electrophotographic method or an electrostatic recording method form, by selective exposure, latent images on an image carrier, uniformly charged, serving as an electrophotographic photosensitive body by a charging means, visualize the latent images by a developing means, and transfer the developed images onto a recording medium. After the developed images are transferred, remaining developer (hereinafter referred to as "waste toners") left on the image carrier is cleaned by a cleaning means and reused for image formation upon being charged uniformly.
A process cartridge has been practically used recently in which process means, such as charging means, developing means, cleaning means, a cleaning container, and so on, are made in a united structure. A user can replace the parts, such as the developers, the image carrier, and so on with those by placing the process cartridge in the apparatus body, thereby rendering the maintenance easier.
Since the image carrier generally has extended the life time of the carrier, recently favored usage, which renders the maintenance easier and corresponds to life times of the essential parts is done by designing a developing means, having some limitation for supplying capability, into an independent cartridge and by designing the remaining process means, such as an image carrier, a charger, a cleaning means, and so on, into a drum cartridge, in a united body.
FIG. 4 shows an example of a conventional process cartridge. The process cartridge 100 shown in FIG. 4 is the above drum cartridge, which includes an image carrier 101, a cleaner blade 102 serving as a cleaning means, and a cleaning container 104 accumulating the waste toners.
The cleaner blade 102 has an elastic contact portion 102a supported by a support member 102b in contact with the image carrier 101 and removes the waste toner remaining on the surface of the image carrier 101. A sealing member 103 made of a material such as mortoprain, sponge, felt, or the like is provided on the opposite ends of the cleaner blade 102 to prevent the waste toner from leaking out of the cleaning container 104. The cleaning container 104 has a volume capable of adequately containing waste toner occurring at the cleaner blade 102 within the life time of the image carrier 101, and can be removed at the time of replacement of the drum cartridge.
Particularly, in a case of a development method using a jumping development or magnetic brush development, it is important to position a developer carrier (development sleeve) for developing images with high accuracy at a prescribed distance with respect to the image carrier 101. Therefore, a contacting roller 105 or the like as a distance ensuring means manufactured with high accuracy is generally placed on each end of the image carrier to ensure the proper distance between the image carrier 101 and the development sleeve (not shown).
In such a case, if the contacting surface 101a of the contacting roller 105 on the image carrier 101 becomes dirty with scattered toner, the toner may adhere to the contacting surface 1O1a, and the prescribed distance may not be kept, disadvantageously. Therefore, the placement of a cleaning member 106, as a part separated from the sealing member 103 provided on the opposite ends of the cleaner blade 102, has been implemented recently for cleaning the contacting surface 101a of the contacting roller 105.
Where the sealing member 103 and the cleaning member 106 are separated members, as shown in the apparatus in FIG. 4, however, developers may accumulate on unclean areas particularly in the process cartridge having a longer life time because the space between those members 103, 106 cannot be cleaned, and the accumulated developers may drop into the apparatus body to disadvantageously make the apparatus inside dirty.
It is therefore an object of the invention to provide a cleaning apparatus, a process cartridge, and an image forming apparatus reducing the uncleanness inside the apparatus by proposing a cleaning method for the surface of the image carrier having no unclean area.